[bmbenson04]

I just got my sti 1 month ago. I've got apexi gt spec catback exaust, turbo xs dual stage boost controller, turbo xs BOV, and I just got a helix dowpipe (bellmouth). Everything was fine but after installing the downpipe I got serious boost creep. I read about this happening with the helix which isn't bellmouth. I turned boost controller all the way down on low and high boost. Anything I can do abouth the boost creep? I'm not hitting fuel cut, but in 4th and 5th I back off the throttle when boost creeps up to about 18psi. Any help would be awesome.

[elucas730]

There are dozens of threads on here about boost creep. All full turboback exhausts will cause boost creep. You will need to port the wastegate on your turbo to fix it.

[bmbenson04]

Would going to an external wastegate also fix the problem?

[Stikya]

Originally Posted by bmbenson04

Any help would be awesome.

Putting just the stock muffler on will also avoid the creep.
I run a TXS stealthback, and have no creep.

[stiperformance]

Originally Posted by bmbenson04

Would going to an external wastegate also fix the problem?

That would work, but you'd have way more trouble that its really worth. Do a search, there is a ton of info on boost creep. Its nothing new and a common problem, not only with the STi, but other turbocharged machines.

Porting the wastegate will help considerably. There are a few threads on porting on here and nasioc.com.

My recommendation to be on the safe side(others might disagree!), wait for engine management then do the engine performance mods. Even an intake will change your a/f ratio drastically. About the onlything that would be safe is a cat-back exhaust. The ECU on the STi is way too smart and complicated to be slapping on mods.

Personally, i'm waiting for the Cobb AccessPort. I have a wrapped catless downpipe and intake ready to go once reliable engine management is available.

[choonzAWR]

some have said that a cat-back exhausts creates boost creeps as well. They've discussed it in the "Modifications" forum. I'm at work and the computer is terrible slow... sorry i can't make links now =[

stiperformance - so what are some safe cat-back exhausts? I want to get the HKS carbon-ti.

[dmacalot]

Originally Posted by choonzAWR

some have said that a cat-back exhausts creates boost creeps as well. They've discussed it in the "Modifications" forum. I'm at work and the computer is terrible slow... sorry i can't make links now =[

stiperformance - so what are some safe cat-back exhausts? I want to get the HKS carbon-ti.

i highly doubt that a catback alone will create any boost creep issues, regardless of which make. from what i understand, a dp and a catback exhaust (some other than the stock one) will cause boost creep. but a catback alone will definitely not. however, i believe there has been one case of someone experiencing boost creep with a dp and stock exhaust, but this is a one in 1000 type thing. good luck!

[bmbenson04]

I need advise on what to do. My boost is creeping upto 18.5-19psi in 5th. Two of my friends say not to worry about it and that its not worth the trouble of removing the turbo and having the wastegate ported. Any advise would be awesome. If ported, do you just do a mild port?

[dmacalot]

boosting that much is definitely not good...and as for your friends, .....just wow. if you need advise, it would definitely be NOT to listen to them. on a more serious note, you have two options. A. port the wastegate (there has been plenty of talk on this, im sure you can do it yourself in a few hours with a dremel, try the search option and some other forums for further info) and B. get rid of the aftermarket cat back, put the stock one back on, and get yourself a header instead 8) but if anything, quit smashing it in 5th and 6th gear until you can decide on a solution to your problem. hope this helps

[stiperformance]

Originally Posted by choonzAWR

some have said that a cat-back exhausts creates boost creeps as well. They've discussed it in the "Modifications" forum. I'm at work and the computer is terrible slow... sorry i can't make links now =[

stiperformance - so what are some safe cat-back exhausts? I want to get the HKS carbon-ti.

The HKS carbon-ti is a decent exhaust...go for it. Any cat-back will be a safe mod. I never heard of anyone having boost creep with a cat-back. I had mine since last August, no creep here. Bolt on a DP = instant creep.

bmbenson04,
I would not be taking advise from your friends if they say not to worry about boost creep!! What you are actually doing is over spinning the turbo and its not working efficiently. The VF39 has its limits and overboosting can lead to turbo failure and/or engine failure. IMO, without proper engine management and/or tuning...your just asking for trouble with any engine performance mod. As for porting, there is a good guy that is a vendor on NASIOC. I suggest sending your turbo to Deadbolt Enterprise(http://deadboltspeed.com/) if you are unsure about porting your turbo. There are plenty of porting how-too's floating around. You just basically enlarge the opening and port out the passage...just don't go wild with the die grinder. Also, FYI, you can remove the exhaust housing from the turbo without removing the entire turbo.

[blueballs]

Where are you located? The only thing to do is port the wastegate. I can do it if you're near central NY. PM me if you want. we've done some local STi's